Photographic material containing softening agent



United States Patent ()fi ice 3,258,338 Patented June 28, 1966 3,258,338PHOTOGRAPIHC MATERIAL CONTAINING SOFTENING AGENT Daniel Alo'is Claeys,Guido Gezellelaan 104, Mortsel- Antwerp, Belgium; Jozef Frans Willems,Sterrenlaan 52, Wilrijk-Antwerp, Belgium; and Marcel Nicolas Vrancken,Ringlaan 31, Berchem-Antwerp, Belgium No Drawing. Filed Dec. 26, 1961,Ser. No. 162,272 Claims priority, application Belgium, Dec. 29, 1960,

40,328, Patent 598,619; June '26, 1961, 40,757; Germany, June 27, 1961,G 32,594

16 Claims. (Cl. 96-67) This invention relates to a process for improvingthe physical properties of a photographic material and more particularlyto an improved process for softening gelatin containing layers of such aphotographic material.

When using gelatin photographic materials it is important to incorporatesoftening agents to the gelatin for rendering the gelatin layers madetherefrom better resistant to treatments at a low relative humidity.Indeed, gelatin layers or gelatin containing layers without softeningagents are very brittle at low degree of relative humidity.

It is known to add to gelatin polyalcohols such as glycerol, lacticacid, substituted phenols monoglycerides of fatty acids or amides suchas formanilide as a softening agent.

As compounds improving the elasticity and the flexibility of gelatinosilver halide emulsion layers, water-soluble long-chained aliphaticamines containing an amide function, metal soaps of sulfonated casteroil which are insoluble in the photographic processing baths,poly(methXy alcohols) and aqueous dispersions of poly(ethyl acrylate)are also added.

As softening agents for gelatin it is further known to use compoundswith a substituted amide group as described in French patentspecification 1,114,721.

Some of these products such as glycerol or other polyalcohols arestrongly hygroscopic and thus injure the photographic and physicalproperties of the layers at rather high relative humidity.

Softening agents for articles made of proteinaceous material are notnumerous since the compatibility of the softening agents with theproteinaceous material is mostly insufiicient.

In choosing softening agents for gelatin used for photographic purposes,there has moreover to be paid attention to their possible influence onthe photographic properties of the materials to be manufactured. In somecases the transparency of the material should not be injured by theaddition of softening agents.

The use of phosphoric acid esters such as tributyl phosphate, tricresylphosphate and triphenyl phosphate as softening agents for articlescontaining cellulose esters is already known since a long time(Kirk-Othmer, Encyclopedia of Chemical Technology, p. 766).

It has now been found that some organic compounds of phosphonic acid andphosphoric acid are excellent softening agents for articles ofproteinaceous materials such as gelatin or casein, and that thesesoftening agents soften layers containing proteinaceous materials ifthey are added thereto in an amount of at least 3% by weight of the dryproteinaceous material.

The phosphonic acid compounds and phosphoric acid compounds usedaccording to the invention correspond to the following general formula:

wherein Each of R and R represents an alkyl radical or an R (O-alkylene)radical, preferably an radial,

R represents a hydroxyl group, an alkyl radical, an

alkoxy radical or an R -(Oalkylene) -O-- radical, preferably an R -(O-CHCH ),,O radical, wherein R represents an alkyl radical, an alkarylradical or an acyl radical,

And n represents an integer of from 1 to 50.

Mixtures of softening agents according to the above general formula canalso be used.

The phosphonic and phosphoric acid compounds used according to thisinvention can easily be prepared from the corresponding acid chloridesor acid anhydrides by reaction with higher as well as with loweralcohols, with monoalkylene glycol alkylethers or with polyoxyalkyleneglycol monoalkyl ethers.

The following compounds and some of their preparations illustrate thepresent invention. Many of these compounds are commercially available.

COMPOUND l.TRIETHYL ORTHOPHOSPHORIC ACID ESTER This compound is marketedas Triethyl Phosphate by Albright & Wilson, Ltd., London.

COMPOUND 2.TRI-N-BUTYL ORTHOPHOS- PHORIC ACID ESTER This compound ismarketed as Tri-n-butyl Phosphate by Albright & Wilson, Ltd, London.

COMPOUND 3.-TRIETHY'L PHOSPHONIC ACID ESTER This compound is marketed asDiethyl ethyl phosphonate by Virginia-Carolina Chemical Corporation,Richmond, Va., U.S.A.

COMPOUND 4.TRI(2-METIIOXYETHYLENE) PHOSPHATE In a three-necked flask of5 liter fitted with a stirrer, a thermometer, a condenser, a droppingfunnel and the necessary calcium chloride tubes, the following mixtureis stirred and cooled till 0 C.:

228 g. (3 mol) of ethyleneglycol monomethyl ether 237 g. (3 mol) ofpyridine 1000 c. of anhydrous benzene While the temperature is keptbetween 0 and 5 C., 154 g. (1 mol) of phosphorus oxychloride aredropwise added in two hours, whereby a precipitate of pyridinehydrochloride is formed. The mixture is still stirred for one hour.Thereupon 500 cm. of water are added and the formed benzene layer isseparated. The benzene is distilled on a water-bath under afractionating column with the air of the reduced pressure of a water-jetpump in order to collect the main fraction of the residue having aboiling range of 202-218 C. at 15 mm. Hg of pressure. After reneweddistillation by means of an oil vacuum pump, the desired fraction isobtained which distills between 158 and 160 C. at about 1 mm. Hg ofpressure.

3 COMPOUND 5 .--TRI (Z-ETHOXYETHYLENE) PHOSPHATE In a three-necked flaskof 5 liter fitted with a stirrer, a thermometer, a condenser, a droppingfunnel and the necessary calcium chloride tubes, the following mixtureis stirred and cooled till C.:

270 g. (3 mol) of ethylene glycol monoethylether 237 g. (3 mol) ofpyridine 1000 c. of anhydrous benzene While the temperature is keptbetween 0 and C., 154 g. (1 mol) of phosphoroxychloride are dropwiseadded in two hours, whereby a precipitate of pyridine hydrochloride isformed. The mixture is still stirred for one hour. Thereupon 500 cm. ofwater are added and the formed benzene layer is separated. The benzeneis distilled on a water-bath under a fractionating column with the aidof the reduced pressure of a water-jet pump. The residue is firstdistilled at about 1 mm. Hg of pressure without fractionation andthereupon fractionated at the same pressure in order to collect thefraction with boiling range of 150158 C.

Yield: 78 g.

COMPOUND 6.TRI(DIETHYLENE GLYCOL MONOMETHYL ETHER) PHOSPHATE In athree-necked flask of 3 liter fitted with a stirrer, a thermometer, acondenser, a dropping funnel and the necessary calcium chloride tubesthe following mixture is stirred and cooled till 0 C.:

252 g. (2.1 mol) of diethylene glycol monomethyl ether 237 g. (3 mol) ofpyridine 1000 cm. of anhydrous benzene While the temperature is keptbetween 0 and 5 C., 154 g. (1 mol) of phosphorus oxychloride aredropwise added in two hours, whereby a precipitate of pyridinehydrochloride is formed. The mixture is still stirred for one hour andthereupon 500 cm. of water are added. The benzene layer is separated andthe benzene is distilled on a water-bath under a fractionating columnwith the aid of the reduced pressure of a water-jet pump. The residue isdistilled at about 1 mm. Hg of pressure in order to collect the mainfraction with boiling range of 150-158 C. Yield: 78 g.

COMPOUND 7.-TRI(DIETHYLENE GLYCOL MONOETHYL ETHER) PHOSPHATE In athree-necked flask of 3 liter, fitted with a stirrer, a thermometer, acondenser, a dropping funnel and the necessary calcium chloride tubes,the following mixture is stirred and cooled till 0 C.:

402 g. (3 mol) of diethylene glycol monoethyl ether 237 g. (3 mol) ofpyridine 1000 cm. of anhydrous benzene While the temperature is keptbetween 0 and 5 C., 154 g. (1 mol) of phosphorus oxychloride aredropwise added in two hours. The mixture is still stirred for 1 hr. Theformed pyridine hydrochloride is sucked off and washed with anhydrousbenzene. The benzene filtrate is evaporated with the aid of a water-jetvacuum pump whereby a pale yellow oil is left. Then the carbitol residueis removed by extraction with hexane, whereupon 80 cm. of 5 N sodiumhydroxide are added. The formed mixture consisting of two layers isfirst heated for 30 min., then cooled and finally extracted with etherfor 8 hours. The obtained ether-extract is dried over anhydrous sodiumsudfate and after drying the ether is distilled. The residue is thenkept for 2 hours on a water bath in the reduced pressure formed by awater-jet pump in order to eliminate the remained traces of pyridine, ifstill present.

Yield: 150 g.

4 COMPOUND 8 The softening agent with the following composition:

O(O HrOH2O)aCiaH21 The softening agent with the following composition/O(CH2 2O)15 i3 27 O=PO(CH:CH2O)i5Ci3H27 is prepared as follows:

A mixture consisting of g. of tridecycloxy pentadecaethylene glycol, 4g. of pyridine, 25 g. of phosphorus oxychloride and 50 cm. of benzene isrefluxed for 1 hr. After cooling, the formed pyridine hydrochloride isfiltered oif and hydrochloric gas is led through the benzene solution.After filtration, the benzene solution is stirred and boiled with 100111. of water and then evaporated to dryness.

COMPOUND 10 The softening agent with the following compositionO(CH2CH3O)5O O-C17Has is prepared as follows:

A mixture consisting of 20 g. of the condensation product of 5 mol ofethylene oxide and 1 mol of stearic acid, 50 cm. of anhydrous ether and0.95 g. of dry phosphorus pentoxide is refluxed for 2 hr. Thereupon theether is distilled.

COMPOUND 11 The softening agent with the following composition isprepared as follows:

A mixture consisting of 20 g. of the condensation product of 10 mol ofethylene oxide and 1 mol of stearic acid, 50 cm. of anhydroux ether and0.66 g. of dry phosphorus pentoxide is refluxed for 2 hr. Thereupon theether is distilled.

COMPOUND 12 The softening agent with the following composition:

O(C Hz-C H2O) 15C O-O17H35 is prepared as follows:

A mixture consisting of 20 g. of the condensation product of 15 mol ofethylene oxide and 1 mol of stearic acid, 50 cm. of anhydrous ether and0.51 g. of anhydrous phosphorus pentoxide is refluxed for 2 hr.Thereupon the ether is distilled.

COMPOUND 13 The softening agent with the following composition2CH2O)5oCOO17 s5 is prepared as follows:

A mixture consisting of 20 g. of the condensation product of 50 mol ofethylene oxide and 1 mol of stearic acid, 50 cm. of anhydrous ether and0.20 g. of dry phosphorous pentoxide is refluxed for 2 hr. Thereupon theether is distilled.

, COMPOUND 14 The softening agent with the following composition isprepared as follows:

A mixture consisting of 16 g. of the condensation product of 6 mol ofethylene oxide and 1 mol of nonyl phenol, 50 cm. of anhydrous ether and1.2 g. of dry phosphorous pentoxide is refluxed for 2 hr. Thereupon theether is distilled.

COMPOUND 15 The softening agent with the following composition A mixtureconsisting of 20 g. of the condensation product of 15 mol of ethyleneoxide, 1 mol of nonyl phenyl, 0.8 g. of dry phosphorous pentoxide andcm. of anhydrous ether is refluxed for 2 hr. Thereupon the ether isdistilled.

COMPOUND 16 The softening agent with the following composition COMPOUND17 The softening agent with the general formula O(CH2CH2O)4 laurylO='PO(CH2-C HzO) lauryl is marketed under the trade-name Hostaphat KL240 by Farbwerke Hoechst A.G., Frankfurt am Main Hochst, Germany.

COMPOUND 18 The softening agent with the general formula O(C Hg CH2O-)soleyl 0=P0 (0 Hz-CHz-O oleyl OH is marketed under the trade-nameHostaphat KO 280 by Farbwerke Hoechst A.G., Frankfurt am Main Hochst,Germany.

The softening agents, according to the present invention can be used invarious compositions of matter. They are especially suited for beingincorporated in gelatin containing layers which form part of aphotographic material.

The phosphonic and phosphoric acid compounds according to the inventioncan favorably be applied in a photographic silver halide emulsion layeror in another gelatin containing layer of a light sensitive photographicmaterial such as an antihalation layer or other backing layer orsupercoat on the emulsion layer as well as in gelatin containing layersof an image-receiving material for the manufacture of' images accordingto the silver complex diffusion transfer process described in US. patentspecification 2,352,014. These softening agents can also favorably beused in the gelatin layer of the socalled blank film described in Frenchpatent specification 1,265,552. These layers may comprise compounds suchas colour couplers, chemical or optical sensitizers, anti-foggingagents, optical brightening agents, wetting agents, developmentaccelerators and matting agents, and can be cast upon paper, glassplates or films e.g. of cellulose esters, polyesters, polystyrene, etc.

The softening agents according to this invention have also a goodantistatic effect. This eifect is strongly pronounced when the softeningagent is incorporated into a layer which is in the outer side of thephotographic material such as a backing layer.

Not all softening agents according to the present invention are equallywell suited for being applied in lightsensitive silver halide emulsionlayers. Softening agents with a molecular weight of more than 1500 andhaving more than 20 oxyalkylene groups in their structure, when appliedin the light-sensitive silver halide emulsion layer in an amount assmall as possible in order to obtain a practically usable softeningeffect give already rise to formation of fog. Such softening agents,however, can be used in another layer than the silver halide emulsionlayer of a photographic material.

The amount of softening agent which can be used de pends on the desiredimprovement of the flexibility of the layers wherein they areincorporated. Preferably these compounds are used in an amount of 10% to30% based on the weight of dry proteinaceous material.

The phosphonic and phosphoric acid compounds ac cording to thisinvention are preferably added before coating the gelatin solution. Inorder to obtain a good dispersion some of these compounds with no morethan alkylene oxide groups, are preferably emulsified in the gelatinsolution by means of emulsifying agents.

The most suitable emulsifying agents are the anionactive wetting agentssuch as sodium salts of alkylsulfonic acids e.g. sodiumtetradecylsulfate and the sodium salt of the condensation product ofoleic acid and methyltaurine of the formula In order to compare theincreased flexibility of gelatin containing layers containing softeningagents according to this invention with the flexibility of usuallytreated gelatin layers folding tests were carried out with a M.I.T.f-old tester. By means of this apparatus the number of folds untilbreaking can be determined.

The following examples illustrate the present invention.

Example 1 The equal parts of a aqueous solution of gelatin at pH 7 to 8,of the compounds identified in the following table, based on the weightof the dry gelatin, are added. After thoroughly mixing the gelatinsolutions are applied onto glass-plates which are treated previously insuch a way that after drying, the gelatin layers can easily be strippedoff.

After solidifying and drying at room-temperature, the gelatin layerswith a thickness of about 150 m are stripped off and cut into stripswith a width of 15 mm. Thereupon the number of folds until breaking aredetermined with a M.I.T. fold tester at relative humidity and 20 C.

The following results are obtained:

Number of folds Softening agent: until breaking None 6 Glycerol 18Compound 1 64 Compound 2 Compound 3 12 Compound 4 32 Compound 5 77Compound 6 38 Compound 7 Compound 8 286 Compound 9 35 Compound 10 117Compound 11 22 Compound 12 15 Compound 13 26 Compound 14 46 Compound 1522 Compound 16 36 Compound 17 119 Compound 18 85 8 The compounds 1, 3,4, 5, 6 and 7 were added to the gelatin solution by means of theemulsifying agent Tergitol 4 (trade-name for a 25% aqueous solution ofsodium tetradecyl sulfate marketed by Union Carbide and Carbon, NewYork, N.Y., U.S.A.).

Example 2 160 cm? of a 10% alcoholic solution of compound 8 are added to1 kg. of a light-sensitive silver halide emulsion comprising g. ofgelatin. This emulsion is cast onto a cellulose triacetate support anddried.

The number of folds until breaking of the emulsion strips determined at30% relative humidity and 20 C. with a M.I.T. fold tester amounts to 20.A similar emulsion strip without softening breaks at the fourth fold.

Example 3 LAYER A To 1 liter of a 8% aqueous solution of gelatincontaining an anti-halation dyestuif, cm. of a 10% alcoholic solution ofthe softening agent described as compound 8 in Example 1 are added. Thesolution is applied onto a cellulose triacetate support and dried.

LAYER B To 1 liter of a 8% aqueous solution of gelatin containingmanganese dioxide, 150 cm. of a 10% alcoholic solution of the softeningagent described as compound 8 in Example 1 are added. The solution isapplied onto a cellulose triacetate support and dried.

The flexibility of both anti-halation layers is tested with a M.I.T.fold tester at 20 C. and at 30% and 36% relative humidity. Two layers Cand D, prepared in the same way as the layers A and B but containing nosoftening agent, are also tested. The following results are obtained:

1. Photographic material comprising a support and at least one gelatinlayer containing a compound of the formula:

each of R and R (equal or different) represents an alkyl radical or a R(O-alkylene) radical,

R represents a hydroxyl group, an alkyl radical, an

alkoxy radical, or a R (O-alkylene),,O-- radical wherein R represents analkyl radical, an alkaryl radical or an acyl radical, and n representsan integer of from 1 to 50,

said compound being present in a quantity of at least 3% by weight ofthe gelatin.

2 Photographic material according to claim 1 wherein said one gelatinlayer is a gelatino silver halide emulsion layer, said compound beingpresent in an amount equal to at least 3% by weight of the gelatin insaid layer.

3. Photographic material according to claim 1 comprising at least onegelatino silver halide emulsion layer and at least one other gelatinlayer free of silver halide emulsion, and wherein each of said gelatinoemulsion layer and said other gelatin layer contain a compoundcorresponding to the formula of claim 1 in an amount equal to at least3% by weight of the gelatin therein.

4. The photographic material of claim 1 wherein said layer contains amixture of 80% of a compound of the formula 5. The photographic materialof claim 1 wherein said layer contains a mixture of 90% of a compound ofthe formula O(CHzCHa-O)C OC17H35 O=PO-(CH2CH2O)5C o C11H35O-(OHZCH2O)5COC17H35 and of a compound of the formula O-(C H2CH2O)5COC11H35 O=PO(CH2CHzO)5COG17H 6. The photographic material of claim 1wherein said layer contains a compound of the formula 0-(0 HzO H2O)4lauryl O=PO-(CH2C HzO-)4 lauryl 7. The photographic material of claim 1wherein said layer contains a compound of the formula O-(C Hz-C Hz0)soleyl 0=1 o-(o H -C HzO)s oleyl 8. Sheet material comprising a supportand at least one gelatin layer containing a compound of the formula:

0R1 O=]!-O R:

wherein R and R each represents an R (O-alkylene) radical or an RCO(O-alkylene) radical R represents a hydroxyl group, an

radical or an R --CO'(O-alkylene) O radical in which formula Rrepresents a hydrocarbon radical, and n represents a positive numberfrom 1 to 50.

9. Sheet metal according to claim 8, wherein said compound is present inan amount equal to at least 3% by weight of the gelatin in said layer.

10. Sheet material according to claim 8, wherein n represents a positivenumber of 3 to 8.

11. Sheet material according to claim 10, wherein the 14. The sheetmaterial of Claim 8, wherein said layer contains a mixture of of acompound of the formula 15. The sheet material of claim 8, wherein saidlayer contains a compound of the formula 16. The sheet material of claim8, wherein said layer contains a compound of the formula ReferencesCited by the Examiner UNITED STATES PATENTS 2,887,381 5/1959 Levy 96942,940,854 6/1960 Gray 9694 2,950,980 8/1960 Hirsch 106125 2,958,60511/1960 Leineretal 106125 3,058,941 10/1962 Birum 106 OTHER REFERENCESButtrey, D. N., Plasticizers, London, Cleaver-Hume Press Ltd., 1957, pp.35, 36.

NORMAN G. TORCHIN, Primary Examiner.

ALEXANDER D. RICCI, Examiner.

C. E. DAVIS, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,258,338 June 28, 1966 Daniel Alois Claeys et al.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

In the grant, line 4, after "Belgium," insert assignors to GevaertPhoto-Producten N.V. of Mortsel Belgium, a company of Belgium lines 13and 14, for "Daniel Alois Claeys, Jozef Frans Willems, and MarcelNicolas Vrancken, their heirs" read Gevaert Photo-Producten N.V. itssuccessors in the heading to the printed specification, lines 4 to 7,for "Daniel Alois Claeys, Guido Gezellelaan 104, Mortsel-Antwerp,Belgium; Jozef Frans Willems, Sterrenlaan 52, Wilrijk-Antwerp, Belgium;and Marcel Nicolas Vrancken, Ringlaan 31, Berchem-Antwerp, Belgium" readDaniel Alois Claeys Mortsel-Antwerp, Belgium; Jozef Frans Willems,Wilrijk- Antwerp, Belgium; and Marcel Nicolas Vrancken, Berchem- AntwerpBelgium, assignors to Gevaert Photo-Producten N.V. Mortsel, Belgium, acompany of Belgium Signed and sealed this 25th day of March 1969.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. EDWARD J. BRENNER Attesting Officer Commissionerof Patents

1. PHOTOGRAPHIC MATERIAL COMPRISING A SUPPORT AND AT LEAST ONE GELATINLAYER CONTAINING A COMPOUND OF THE FORMULA: